Andy comments:

In addition, I would ground the coax outer shield conductor to the
tower ,
which should have a ground to earth SEPARATE from the concrete
mounting block.....
This will have NO effect on the signal inside the coax, and in the
event of
a lightning strike, the center conductor, if hit, will arc to the coax
shield
anyway...... A lighning arrestor wouldn't hurt, tho... It will help to

protect your inside equipment, tho the results are unpredictable....

Andy W4OAH